What causes yellow leaves on melons?
Yellow leaves appearing during melon cultivation is a fairly common phenomenon. It affects the overall yield of melons and greatly reduces melon quality. If managed improperly, it can also affect the sweetness of melons. So why do melon leaves turn yellow? Let's find out together with the editor.
1. Nutrient deficiency
Melons need a variety of nutrient elements during growth, and the main cause of yellow leaves in melons is nutrient deficiency. Nitrogen deficiency, phosphorus deficiency, potassium deficiency, calcium deficiency, iron deficiency, copper deficiency, and magnesium deficiency can all cause leaves to turn yellow. Moreover, the symptoms of each deficiency differ. With nitrogen deficiency, leaves turn yellow-green, old leaves dry up, and new leaves are small and few; with phosphorus deficiency, plants are short and small, and leaves are dark green and dull; with potassium deficiency, the leaf margins turn yellow first and gradually become scorched, and in severe cases the entire leaf withers; with calcium deficiency, the leaf margins turn yellow, but old leaves remain green; with iron deficiency, leaves become pale yellow, but the veins remain green, and later the entire leaf loses green color and drops off; with copper deficiency, the green color at the leaf tips gradually fades; with magnesium deficiency, leaf color turns yellow, most obviously at the leaf tips, but the veins remain green.
2. Fertilizer damage
Somewhat similar to nutrient deficiency, if too much fertilizer is applied during cultivation, it causes fertilizer damage to the plants, which is also a common cause of yellow leaves. Especially just after fertilizing or after spraying pesticides, yellow leaf symptoms generally appear within 1-2 days, and the affected area is relatively large and fairly widespread. For yellow leaves caused by fertilizer damage, increasing watering or spraying urea on the leaves can relieve the symptoms.
3. Climatic causes
Yellow leaves in melons are also somewhat related to climate. Many farmers use black film mulching technology to raise soil temperature and speed up melon growth, but during hot summer periods, black film not only absorbs heat but also prevents heat dissipation, thus affecting root growth and causing premature aging and yellow leaves. In addition, long periods of rainy weather or a closed canopy between plants can also cause leaf yellowing, so climate changes should be noted during cultivation and proper management should be carried out.
4. Diseases
Another cause of yellow leaves is disease. The representative disease among them is bacterial leaf blight, also known as leaf spot disease, which mainly occurs in high-temperature and high-humidity environments and spreads very easily. When the disease occurs, yellow-brown lesions appear on the leaves, gradually expand and merge, and in the later stage cause large areas of dead spots on the leaves, preventing the leaves from carrying out normal photosynthesis. In the early stage of the disease, streptomycin can be sprayed for control; at the peak of the disease, azole fungicides mixed with thiodiazole-copper or longkejun can be used for control.
The above is an introduction to what causes yellow leaves in melons. We hope it can help you. If you want to learn more related knowledge, please keep following us.